Ever look down at the weather app on your iphone and see some small text under the temperature that reads “Unhealthy Air Quality for Sensitive Groups?” Ever wonder what that means? And if you should be concerned?
Today we are going to be discussing exactly what that unhealthy air quality for sensitive groups warning means, and what you can and should do when you see it.
While this blog has been heavily nutrition-focused lately, but this post is going to tap into my Environmental Health Science MPH. May as well use it, right?
What is AQI?
Before we can understand what “Unhealthy Air Quality” means, let’s first talk about what it is and how it’s measured. Air Quality Index (AQI) is a term used by government agencies to communicate with the public how polluted the air is or is forecasted to be.
Generally speaking, the higher the AQI, the greater the public health risk. Different governments have different national air quality standards to classify different health risks and communicate these risks to their citizens.
How is the AQI Calculated?
In the US, the EPA calculates the AQI for five major air pollutants regulated by the Clean Air Act, including particulate matter (read my whole post about what PM is here), carbon monoxide, ground-level ozone, sulfur dioxide, and nitrogen dioxide.
Air monitors collect and record pollutants over 1,000 locations across the country. The raw data is used to develop a separate AQI for each of the 5 mentioned pollutants. The highest of the AQI values from these 5 is reported as the AQI value of the day.
What do the AQI Values mean?
The AQI runs from 0 to 500. As mentioned before, the higher the AQI, the greater the level of air pollution, and thus, the greatest risk to human health. When your phone reads “Unhealthy for Sensitive Groups,” the AQI is between 101-150.
At-risk groups, such as the elderly, young children, those with asthma, bronchitis, emphysema, or other respiratory illnesses or cardiovascular diseases, may be at risk of serious health risks, or are at risk of exacerbating existing illnesses.
Specifically, high levels of ozone may impact people with lung disease, children, and older adults are people who are active or exercising outdoors. High levels of particle pollution may impact people with heart or lung disease, children, and older adults.
Details on every AQI level are below:
The list below explains the different health risks associated with different AQIs:
- An AQI of “0-50” is considered “Good.” Air quality is considered good, and air pollution is not seen to be a risk.
- AQI values of 51-100 are considered “Moderate”. Air quality is considered acceptable, but some pollutants may impact certain people.
- AQI of 101-150 is where the whole “Unhealthy for Sensitive Group” classification comes in. When AQI is in this range, most people should be okay given the current air quality; however, certain sensitive groups (such as young children, the elderly, and those with existing cardiovascular and/or respiratory illnesses) may be at risk of developing or exacerbating health issues.
- AQI of 151-200 is considered “Unhealthy.” When the AQI is in this range, everyone may experience some level of adverse health impacts, while those considered at-risk are likely to experience more serious effects.
- AQI of 201-300 is considered “Very Unhealthy” and it’s likely that the entire population would be experience negative health effects. Typically, this would elicit some sort of warming.
So what kinds of health risks or adverse health impacts can one experience if the AQI is high?
Different air pollutants impact human health in different ways. Primarily, these pollutants impact the cardiovascular system and respiratory system.
For example, surface-level ozone can increase risks of several health conditions. In addition to irritating the respiratory system and reducing lung function, ozone can actually inflame and damage cells that line the lungs, and make the lungs more vulnerable to infection. Unhealthy air can also aggravate asthma and other chronic lung diseases.
But polluted air can hurt more than the lungs! High levels of PM can increase the risk of cardiovascular disease, and lead to chest pain, palpitations, and fatigue.
Carbon monoxide, another particle used to calculate AQI, can enter the bloodstream through the lungs and bind to hemoglobin, reducing the amount of oxygen that makes its way to body’s organs and tissues.
This can negatively impact those with cardiovascular disease or heart conditions, and can lead to fatigue and affect mental alertness.
Sulfur dioxide can also aggravate asthma and cardiovascular disease.
How Can I check the AQI?
Many forecasts include AQI values (including the iPhone forecast, if you scroll down and look at the number in the lower-left corner). Or visit airnow.gov.
What can I do to avoid negative impacts of unhealthy air?
Keep an eye on the AQI report and forecast. If the AQI is running high, avoid unnecessary physical exertion outside (ie, if you like to run outside, consider running indoors in an air conditioned setting).
Why? Physical exertion requires more rapid respiration, which means greater inhalation rates and greater exposure to unhealthy air.
If you can, remain indoors and use an air filter, if that’s available to you. Even if you can’t filter your whole living space, getting a filter in at least one room, and sleeping in that room, can reduce exposure. The EPA has an air cleaner and filter guide here.
Keep your windows closed and try to maintain a clean living space – but so long as the AQI is high, don’t vacuum unless your vacuum has a HEPA filter; this will only stir up more dust.
Avoid burning anything – cigarettes, candles, and fireplaces.
Air masks are another option if AQI is very high. Casual dust masks you’d wear to avoid inhaling sawdust won’t cut it (those are made to block out large particles).
Also, I’m sorry to insult Coachella fashion, but scarves and bandanas also won’t do the trick. Make sure you get a respirator known as N-95 or P-100. The state of California has a useful guide for using these masks correctly for air pollution from wildfires.
If you are feeling ill, and/or have an underlying cardiovascular or respiratory illness, seek medical help immediately. And make sure you check on your family and friends who may be considered “at-risk” and offer to help them, if needed!
When your phone says the air quality “Unhealthy Air Quality for Sensitive Groups,” that means the AQI is a bit elevated. Practice caution by reducing physical exertion outdoors, especially if you are considered part of a vulnerable group (the elderly, children, and those with existing cardiovascular and respiratory illnesses).
Try to stay inside and use air filters, if they are available to you, and reduce creating any other air pollution in your space by doing things like burning candles or smoking.
Take care of yourself, watch the AQI forecast, and rest until the AQI has dropped. And of course, if you feel sick, seek medical attention!
Thank you as always for reading! You can watch the video version of this article here.